• Journal of Korean Society of Forest Science
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• v.99 no.3
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• pp.298-303
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• 2010

To explore on the defense strategies against hervivory of Juglans regia and J. mandshurica, morphological characteristics of the leaf, leaf domatia structure and the number, herbivores insects and mites on the leaves, collected from the trees growing in Mt. Chiak, Mt. Cheongtae, Mt. Jungwang, Namyangju-si and Wonju-si, were investigated from May to October, 2009. Domatia of J. mandshurica revealed tuft type, these of J. regia revealed pocket+tuft type. Domatia number per leaflet proved the higher figures, 28.3/leaflet for J. mandshurica, and the lower, 19.6/leaflet for J. regia. Leaf surface trichomes of J. regia revealed stellates only on the domatia structures, and that of J. mandshurica does dense stellates and glandular hairs on the leaf-blade and vein. Predatory mites' number per leaflet proved highly significant differences among tree species, and mean of predatory mites was higher values (4.8/leaflet) in J. mandshurica and lower values (3.5/leaflet) in J. regia. Small amount of nectar are found distal veinparts on the leaf margin of J. mandshurica. Dense glandular hairs on the lower leaf surfaces of J. mandshurica estimates useful strategy against herbivory. It may be possible to breed J. regia for better expression of leaf traits such as dense glandular hairs that increase predator populations and efficacy.

• Korean Journal of Environment and Ecology
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• v.38 no.1
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• pp.48-54
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• 2024

This study conducted a survey from April 2021 to December 2022 to investigate habitat factors affecting bird diversity in the region between Cheonwangbong Peak and Aghwibong in Baekdudaegan protected area, South Korea. Since the region has a spatial scale of 736.4 km² and is an area where a wide variety of habitats are mixed, we selected 20 survey areas of 3 km x 3 km by analysis of habitat homogeneity. As a result of analyzing the relationship between habitat environment and bird diversity in the survey area, it was found that the diversity of bird communities was directly or indirectly related to the diversity of terrestrial insects, slope, average habitat area, mean size of patches, elevation, and forest type, and distance from agricultural land. The slope of habitat, forest type, and distance from agricultural land affect the occurrence of food sources directly and indirectly, and the average area of habitats and forest type is closely related to the structural diversity of habitats. Therefore, it is determined that the diversity of bird communities is affected by the amount of food generated within the habitat and the diversity of habitats. It is determined that the relationship between bird communities and habitat environments in this surveyed region can be basic ecological data for establishing forest management measures to promote the diversity of bird communities.

• Journal of Microbiology and Biotechnology
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• v.17 no.3
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• pp.420-427
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• 2007

We investigated the temperature effects on the virulence, development, reproduction, and otility of two Korean isolates of entomopathogenic nematodes, Steinernema glaseri Dongrae strain and S. longicaudum Nonsan strain. In addition, we studied the growth and virulence of their respective symbiotic bacterium, Xenorhabdus poinarii for S. glaseri and Xenorhabdus sp. for S. longicaudum, in an insect host at different temperatures. Insects infected with the nematode-bacterium complex or the symbiotic bacterium was placed at $13^{\circ}C,\;18^{\circ}C,\;24^{\circ}C,\;30^{\circ}C,\;or\;35^{\circ}C$ in the dark and the various parameters were monitored. Both nematode species caused mortality at all temperatures tested, with higher mortalities occurring at temperatures between $24^{\circ}C\;and\;30^{\circ}C$. However, S. longicaudum was better adapted to cold temperatures and caused higher mortality at $18^{\circ}C$ than S. glaseri. Both nematode species developed to adult at all temperatures, but no progeny production occurred at $13^{\circ}C\;or\;35^{\circ}C$. For S. glaseri, nematode progeny production was best at inocula levels above 20 infective juveniles/host at $24^{\circ}C\;and\;30^{\circ}C$, but for S. longicaudum, progeny production was generally better at $24^{\circ}C$. Steinernema glaseri showed the greatest motility at $30^{\circ}C$, whereas S. longicaudum showed good motility at $24^{\circ}C\;and\;30^{\circ}C$. Both bacterial species grew at all tested temperatures, but Xenorhabdus sp. was more virulent at low temperatures $(13^{\circ}C\;and\;18^{\circ}C)$ than X. poinarii.

• Journal of Korean Society of Forest Science
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• v.55 no.1
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• pp.47-54
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• 1982

Soft X-ray photography was used to study some characters of seeds, such as fullness, damage by blight and harmful insects and degree of mechanical damages, degree of development of embryos and endosperms, size and position of cotylendons, existence and position of twin seed. Thirty nine species of woody plants (31 angiosperms and 8 gymnosperms)and four species of herbs were examined in this study. The results showed that through the mechanism of the selective sensitivity of seed structure of soft X-ray, seed characters mentioned above could be recognized regardless of size of seeds and thickness of seed coat. We concluded that it is possible to use soft X-ray photography reliably to find out the various characters of seeds.

• Korean journal of applied entomology
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• v.59 no.2
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• pp.83-91
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• 2020

We assessed efficacy of spraying pesticides from an unmanned helicopter to control two insect species, Monochamus alternatus and M. saltuarius, which are vectors of pine wood nematodes. Control efficacy of thiacloprid FL (33×), acetamiprid ME (33×), and flupyradifurone SL (33×) was determined by placing caged insects in the canopy of pine trees (Pinus sp). Water-sensitive paper was used to record the spray pattern of pesticide droplets and the degree of coverage; furthermore, we investigated peripheral scattering due to spraying. The three pesticides showed > 96% control efficacy against the targeted vectors, and pesticide droplet spray patterns were similar. Peripheral scattering was observed up to 20 m in front and 10 m to the left, right, and behind the targeted area. The coverage index of all the directions at 5 and 10 m distance was 6-7 and 2, respectively.

• Journal of the Korean Wood Science and Technology
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• v.35 no.1
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• pp.64-72
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• 2007

The biodeterioration behaviors of square post to support the wooden printing blocks Shelves in the Janggeongpanjeon were investigated according to the positions and parts of square post, and environmental conditions. It was found that a high differences of deterioration in the progressing levels of wood decay, according to the positions and parts of square post, and environmental conditions. The decay levels were very high and still progressing in the contacted areas with stone foundation which are about up to 50 cm above it. In the decay type, white rot fungi was mainly affected in the inside of building which mainly made of softwood. The decay in the square posts to support the wooden printing block shelves inside of building was worse in the rear side, compared to front side. The insects was not found in most of square posts excluding the post which was neighboring at the infected round column by insect.

• Korean Journal of Ecology and Environment
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• v.47 no.1
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• pp.24-31
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• 2014

This study was conducted to clarify the seasonal and elevational pattern of herbivore's feeding pattern in a temperate deciduous forest. We investigated the herbivore's feeding activity for three years (2011~2013) at three survey sites in Mt. Jirisan National Park (Piagol, Siamjae, Nogodan). We selected target tree species based on the dominance across the sites (Quercus, Acer, Rhododendron and Carpinus) and scored herbivore's feeding activity every one or two weeks from April to June using leaf damage index. We found that the herbivory started early at the low elevation site (Piagol, ${\approx}300m$), and the highest feeding activity occurred at the mid elevation site (Siamjae, ${\approx}900m$). At the highest elevation site (Nogodan, ${\approx}1300m$), the herbivory started late, but the total feeding activity accumulated quickly. Compared to the breeding time of Varied tit, an insectivore bird, it was overlapped with the feeding activity period of herbivores, suggesting close interaction among plants, insects and birds in this deciduous forest. We suggested a need of long-term monitoring of this tri-trophic interaction since duration of herbivore activity can be changed followed by climate change.

• Korean Journal of Environment and Ecology
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• v.32 no.2
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• pp.147-153
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• 2018

There are few available studies for insect diversity in relation to coastal dune despite the unique landscape features and high conservation value. Therefore, this study compared ground beetle assemblages inhabiting between windbreak forests and sand dunes in the Taeanhaean National Park. It investigated five windbreak forests and three coastal dunes using pitfall traps from middle of June to middle of October in 2014. A total of 2,335 ground beetles belonging to 30 species of 15 genera were collected. Synuchus arcuarticollis (158 individuals) and Dolichus halensis halensis (153 individuals) were dominant of 25 specifies collected from sand dunes while Synuchus arcuarticollis (1,630 individuals), Synuchus nitidus (130 individuals), and Synuchus cycloderus (42 individuals) were dominant of 14 species collected from windbreak forests. The similarity of ground beetles compositions in sand dunes and windbreak forests was significantly low at 27.4%. The results of this study showed that sand dune geographical features found in the Taeanhaean National Park had different insect assemblages from windbreak forests. It will be the useful information for conservation of insects in the future.

• Journal of the Korean Wood Science and Technology
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• v.35 no.1
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• pp.51-63
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• 2007

The biodeterioration behaviors of wooden parts in the Janggeongpanjeon built in 15 century were investigated according to the types of wood species, positions and parts of wooden column, and environmental conditions. It was found that a high differences of deterioration in the progressing levels of wood decay, according to the types of wood species, positions and parts of wooden column, and environmental conditions. The decay levels were high in the contacted areas with stone foundation which are about up to 8~40 cm above it, although it was shown the many of wooden parts of the round columns are still good condition. In the case of decay type, it was shown the brown-rot in many of the columns at outside of building which made of hardwoods. The decay in position of the columns was most serious in the directions of east-north, west-north and north. It was also indicated that the durability of Zelkova serrata was higher than other wood species of the round columns, while it was in inferior anti-insects.

• The Korean Journal of Ecology
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• v.12 no.1
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• pp.9-20
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• 1989

Annual production and decomposition of litter were studied in piuns rigida platation in Mt. Kwan-ak. The peak time of litter production was October-November. The litterfalll at that time was 54% of annual litter production. But the peak time of litterfall of reproductive parts was Junejuly. The peak times of litter production in Alnus hirsuta plantation were June-July, and November. It is thought that difference of seasonal distribution of letterfall between two forest types were assigned to litter falling factors such as temperature and insects. Total amount of letter loss increased according to time. Particulary, the peak time of loss rate was July-August. It was shown that the protein and phosphorus were accumulated in the letter for an experimental period. The amount of crude protein increased to 150% of initial amount. The amount of potassium was increased by August and then decreased rapidly. The contents of crude fat, holocellulose, lignin, and Na were decreased slowly. The loss of holocellulose was the largiest among them. Calcium was in steady state. It was thought that this variation pattern was assigned to leaching of soluble parts by high temperature, rainfall and growth rate of microorganisms.